Refracting-stereoscope.



R. H. WAPPLER.

REFHACTING STEREOSCUPE.

APPucATloN FILED APR. 24. 19u.

Patented Juney 18, 1918.

9 "27 .31 .5 Ja f3 R. H. WAPPLER.

REFHACTING STEREOSCOPE.

APPLICATION FILED APII.24. I9I7.

Patented June 18, 1918.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

REINHOLD H. WAPPLER, OF NEW YORK, N. Y., ASSIGNOR TO WAPPLER ELECTRIC COMPANY, INC., A CORPORATION OF NEW YORK.

BEFBACTING-STEREOSCOPE.

.Application led April 24, 1917.

To all whom it may concern.'

Be it known that I, REINHOLD H.'WAP rLnR, a citizen of the United States, residing in the city of New York, boron h of Manhattan, in the county and State o New York, have invented certain new and useful Improvements in Refracting-Stereoscopes, of which the following is a full, clear, and exact description.

My invention relates to stereoscopes, my more particular purpose being to produce a device of this character in which I use a pair of prisms so formed and arrangedias to attain the following results:

I. To adapt the stereoscope for viewing pictures or images of large size, such as 14 by 18 inches, while retaining Various advantages peculiar to the use of prisms.

II. To so direct the light rays that all of those entering either eye are crossed rather abruptly by all of those entering the other eye, so that large pictures or images in pairs may be viewed at comparatively short range, the eyes of the observer meanwhile remaining approximately normal in directive position-'thus shortening the working distance and promoting compactness.

III. To render the device peculiarly adaptable for X-ray negatives or other pictures or images, using a translucent plate, illuminated by light applied to its back.

IV. To avoid the necessity for precise adjustment in various adjustable parts; to prevent all necessity for undue strain upon the eyes of the observer incidental to use of the device; to prevent slight lateral displacement of the prism relatively to the picture or image from interfering with the stereo-v scopic vision; and to prevent or greatly .alleviate chromatic aberration.

These and other objects sought to be accomplished are explained more in detail in the descriptive matter to follow.

For the sake of conciseness I will describe only a single form of my apparatus, it being understood, however, that this form is merely t pical, and that the structure and action o my device may be varied within limits, defined by my claims.

Reference is made to the accompanying drawings forming a part of my invention, and in which like letters indicate like parts in all of the views.

Figure 1 is a perspective of my improved stereoscope complete and ready for use..

Specication of Letters Patent.

Patented June 18, 1918.

serial No. 164,089.

F ig. 2 is a diagram for elucidating the optical principles involved.

Fig. 3 is a diagrammatic section through the prisms and casing for supporting the same.

A supporting tube 4 is mounted upon 'a spider 5, the latter being provided with leveling screws 6.

A supporting rod 7 extends into the supporting tube 4, and is detachably held by a set screw 8 and thus rendered adjustable.

The rod 7 carries a clamping disk 9 inte-.

gral with it. Mating this clamping disk i) is another clamping disk 10. The clamplng disks are forced together by a bolt 11 and wing nut 12. Carried by the clamping disk 10 is a rod 13, carrying a T 14. Extending from this T is a straight tube 15, and extending telescopically into the latter is an L-tube 16. A rod 17 lits telescopically into the adjacent end of the L-tube, and is detachably held by a set screw 18. This rod 17 is ad- Justable relatively to the L-tube, and the L- tube is adjustable relatively to the straight tube 16.

The rod 17 and all parts carried by it are adJustable angularly in relationto the rod 7.

A casing 19 is mounted rigidly upon the upper end of the rod 17, and serves as the barrels of the stereoscope.

A pair of lanterns 20, 21, are provided with translucent plates 22,23, which in this particular instance are X-ray negative plates. These negative plates are illuminated by the lanterns, each of which contains one or more lamps, not shown. The lanterns are provided with hinge eyes 24, 25, which fit upon the rod 13, so that the lanterns can swing upon the axis of this rod as a center.

A pair of pit-men 26 are by pivot pins 27 connected to the lanterns, and by a single pivot pin 28 these pitmen are also connected to a sleeve 29, which is slidably mounted upon the straight tube 15. A set screw 30 holds the sleeve 29 normally fixed in relation to the tube 15.

The operator, by loosening the set screw 30, can loosen the sleeve 29, and by sliding this sleeve along the straight tube 15 and tightening the set screw 30, he can adjust the lanterns 20, 21 and plates 22, 23. Thus the plates 22, 23 can be turned so as to be separated by different angles.

By adjusting the Ltube 16 relatively to the straight tube 15, the distance of the cas- 5 casing relatively to the kplates 22, 23 may be regulated at will. 1

` Instead of the X-ray negatives 22, 23, pictures or images of any other type may be substituted, if desired, and the illumina# tion may be caused by the lanterns or by lightr from any suitable source. Tf ordinary photographs or analogous pictures are used, they need-not be translucent andmaybe illuminated from the frontthat is, upon their exposed surfaces facing the casing 19.

The vplates 422, 23 are in this instance quite large, say 14 by 18 inches, and are close to gether as well as close to the casing 19.'v

The casing 19 has a sheet metal bodyy por- 20 tion 32 and a portion 33 of arcuate form, these parts being so disposed and arranged as to provide open slots 34, 35 serving as visual openings, the eyesv of the observer being shown adjacent these openings, at

Two portions 38, 39 of sheet metal, integral with the casing, are bent inwardly or toward each other as shown in Fig. 3, in order to exclude the entrance of undesirable light.

A pair of prisms are shown at 40, 41, each being provided with three flat facets 42, 43, 44, each having a distinct optical function. Each prism is also truncated to form a facet 85 45. The facets 45, 45 are practically idle and resting against the adjacent inturned portions 38, 39, of the casing. y The prisms are so tted into the casing as to be held securely in position by the pres- 40 sure of the sheet metaltop andbottom members of the casing upon the adjacent top and bottom surfaces vof the prisms. Any suitable mechanical arrangement may' be substituted, however, for holding the prisms within the casing. l ,a f

Each facet 42 is bare and throughoutjts entire surface is exposed to light entering through the large opening between the p0r tions 38, 39 of the casing, j

My purpose in truncating the prisms so as to form ythe twosmall facets v45 is to remove a yportionof the prism which is "-notonly useless but if allowed to remain would cause the two lields of View to interfere with each other, and would also cause more or less chromaticaberration. By truncation of the prisms these undesirable 'effects are avoided and compactness is promoted by the shortening of the working distances from the prisms to the pictures or images. Y Other-'di mensions being equal, the eldoffyision is thus enlarged.v I i No silvering or yanal'igous surfacing 1s necessary` for .any ofthe: facets 42, ,'43, 44.y It will be noted that each prism'40, 41 is double acting. That is to say, it has three active or truly optical surfaces, and isso proportioned and arranged that the light in passing through it istwice reflected, vand of course ltwice refracted. Thus many optical faultspeculiar to prisms of ordinary form kare completely removed or greatly alleviated by the use .of my improved prisms, owing to the fact that an optical fault due to internal reflection of light from one facet may be compensated, neutralized or offset by internal reiection of the same light from a secondv facet. t l

I find'itfdesirable that the angle between the facets42 and 44 be double the angle be- 80k *i sentative of light rays.. The plate 22 being illuminated as abovey described, light'rays radiate fromv practically allv parts of this plate. lSome of these light rays, represented by thelines46, 47, 48, converge more or less and pass through the prism 40. They enter'through the adjacent portion of the facet 42 and in so doing are refracted to 100 different extents, depending upon the angularity ofthe lines 46, 47 48 relatively to the facet 42.v As thel rays reach the facet 43 they are rvreiected 'internally of the prism, and' they continue/to converge till theyreach 105 facet 42. Here they are again reflected'internally of the prism,and, still'converging, ,f they now pass out through the'facet 44j, being refracted in so doing, and enter the right 'eye'36 of the observer. Similarly the 110 rays represented by the lines 49,' 50,z 51 leave theilluminated plate 23,! and pass through the prism, being twice refracted andV twice refiected, yet all the while converging so .as

to enter .they lefteye 37 kof the observer. j v115 n Ther netre'sult'is thatv the? rightj eye V36, looking Istraight ahead, has a ie'l'd'iofview commensurate Iwith the entire`- operating surface ofthe plate 22,a'nd the left' eye37 y has a view. commensurate with the operatf ing surface of the plate 23.

The iieldzof view represented bythe lines 46, 47, 48 'crossesthe field .of View represented by the lines 49, 50, 51 so that'the two iieldsclear each other in the'sense that 125 eachjplate 2 2, y23 is y"visible in its entirety and'that these' plates donot overlap 1 each other,Y VYet owing .to they 'great angularity of thelines46, 47', 48 relatively to the facet 42 fthe'pris'mpao, and 'of the 1ines4a5o, iso

relatively to vthe facet 42 rof .the prism 41, the plates 22, 23, may `be placed surprisingly close ,to Vthe prisms, and may be of considerablesiza'as above explained. Of course.otherthings being equal, the longer theplates 22, 23 the farthertheymust be spaced Vfromthe prisms, rbutfor a given distancefrom prisms to platesthe plates may .be Teliflvely 1.31183: and fol" 5%. gwen SIZ@ 0f plates v,the distance from prlsms lto plates may `berelatively short. Upon this account a slight increase'in the distance from the prisms tothe plates will enable the use of -platesuoffmuch :larger Asize than would otherwise'be possible.

I do notideem `it necessary toexplainthe ivellknown principle of the stereoscope, namely, the manner in which two pictures, each with a ,fiat surface, are caused to virtually produce a single image having the tages above recited, as well as many others.

Duplicate pictures, images or material objects, as the case may be, when seen through it, are remarkably clear in general outline as well as in detail. Any particular part may be closely scrutinized, as there is very little tendency toward confusion of lines, conversion of straight lines into curves, or blurring of lights and shadows. Lateral displacement of the eyes of the observer relatively to the prisms has very little effect. In fact the operator while using the device may Within reasonable limits move his head up or down or sidewise, or even give one of his eyes a slightly higher elevation than the other without materially disturbing his vision.

My improved stereoscope has no precise focal distance, and upon this account may 'be used with equal facility for enabling' the operator to view objects of small size, placed close to the prisms, or objects of larger size, placed farther away from the prisms. In many instances the objects can be seen Yto better advantage than would be the case if they were seen through spectacles or even through the naked eyes. Again, in some lines of development, such as Xsray work, it often happens that the pictures, and especially negatives, are large simply because they are shadowgraphs of objects which are themselves of considerable size. For instance an X-ray negative showing a mans ribs must almost of necessity be of large size owing to the manner in which X-ray negatives are usually made. My prisms above described are well adapted for such negatives, because notwithstanding their large l size theycan be brought into close proximity to the prisms and thus viewed to Ybetter advantage while, as above explained,

,scope as it would if seen by the naked eye.

I do not limitmyself to the kprecise mechamsm shown7 as variations therefrom may .be .made without departing from the invention which is commensurate with my claims.

Ifclaim: n v

1. In a stereoscope the combination, with :means for supporting a pair of visual objects to be observed, of a pair of optical prisms each associated with one of said visual objects, each prism having a large facet and two smaller facets, each of said smaller facets being inclined relatively to said large facet, the angle of inclination for one of said smaller facets being substantially double the angle of inclination of the other of said smaller facets.

2. In a device of the character described the combination, with means for supporting a pair of visual objects to be observed stereoscopically, of a pair of optical prisms each associated with one of said objects, each prism being provided with a plurality of facets so distributed that a group of convergent light rays in, passing from the visual object through the prism to the eye of the spectator, is refracted in entering and also in leaving said prism and is twice reflected internally thereof, said prisms being so located relatively to each other and to the objects to be observed that the group of convergent light rays from one of said objects is crossed by the group of convergent light rays from the other of said objects.

3. In a device of the character described the combination of a pair of pictures and a pair of prisms for viewing said pictures stereoscopically, said prisms bein so formed iand so located relatively to said pictures that a group of convergent rays of light passing from one of said pictures through its corresponding prism is crossed by a group of convergent rays of light passing from the other of said pictures through the other of said prisms, and means for adjusting said pictures to different angles rela- Arelativi-Sly to each other, in order to render said vpictures normal relatively to 'said prisms -when thusspaced at differentudistances from said prisms.' l y 5. In a stereoscopethe combinatlon'of a lpair o'f 'visual objects'to be observed anda pair-of prisms for viewing the same stereoscoplcally, each prism beingprovidedgvvith 'facets so arrangedI that'light; in'kp'assin'g yfrom eitherof said;y objects 'throughf the 'prism associated therewith is twice'reflectedv and twice refracted, each" prism beingptrun- 'cated in "order to prevent the 'visual objecty associated With lone prism frombeing seenv through the prism.

'6. In a stereosc,ope,th`e combinationof means for 'supporting'aipair of vvisual" objects, aE pair of prisms` for viewing said` ob- Copievs o f Patent may ybeol'atpain'ul vfer jectsV stereoscopieal'ly, each prism/'having facets so distributed as to cause light,in

passing vfrom `the object through Aits correspondingl prism, to be twice" reiected Vand twice refracted', each prism being truncated,

and means for' 'preventing-the entrance of light into the'PiSm at the point Where it is thus truncated. y

" 7 'In' a'V device of the character described the combination, With'v means for rsupporting 'a' visual object to be observed, of an optical prism provided With a large'facet and with la plurality" of smaller "facets, 'all' of said facetsbeing fso inclined relatively to each other and said prism being so'psitionedl u '.relativelytosaid visual object,'that a group of llight rays, A"in passing! from 1the visual' object tofth'e ey'of vthe spectator, 'enters'th'e prism through a portion of the larger facet, l, 'is reflected internally of the'fpri'sm by onel of the smaller facets and also 'by' a" portion rof said 'larger facet yand 4leaves'nth'eprism by vpassing 'out throughanother :of :said smaller facets(l "l f REINHOLD WAPPr-.Ea

ve `cents each, by addressing the "omi'nissiner of Intenta WashingtomDQG. f 

